My objectives are (1) to gather data on purified alkaline phosphatase from leukocyte granules of normal human subjects and patients. (2) To compare data obtained from alkaline phosphatase of leukocyte granules from patients with a variety of disease states in which the activity of alkaline phosphatase is known to be either elevated or depressed. (e.g. polycythemia vera, chronic myelogenous leukemia, myeloproliferative disorders, etc.) Further characterizations of specific granules of human leukocytes by chemical analysis of their constituents will also be undertaken.